Several phenomena exist which involve the conversion of solar energy into electrical energy. The common solar cell, such as the silicon solar cell or solar cells made from various semiconductor materials, are generally based upon the photovoltaic effect wherein the direct conversion of solar radiation into electrical energy occurs across a PN junction. Alternatively, electron-hole pairs can be created at an interface by the Schottky effect. In the photogalvanic effect, solar radiation impinges upon a photoionizable material which undergoes redox reactions at the respective electrodes in contact with the photoionizable media. Generally, the devices using the aforementioned effects do not have the capability of storing the charge generated during the period of irradiation. Charge storage of these devices has been accomplished by coupling an external capacitor or storage battery to the device.
We have discovered that it is possible to construct a thin photosensitive cell having an integral charge storage media therein. This charge storage media is believed to function by storing a charge in potential traps or wells.